{"id":"USN-8198-1","summary":"python-tornado vulnerabilities","details":"It was discovered that Tornado incorrectly handled parsing of large\nmultipart request bodies. An attacker could possibly use this issue to\ncause a denial of service. (CVE-2026-31958)\n\nIt was discovered that Tornado did not properly validate characters in\ncookie values. An attacker could possibly use this issue to inject\narbitrary cookie attributes. (CVE-2026-35536)","modified":"2026-05-20T16:06:18.677977899Z","published":"2026-04-22T17:52:30Z","related":["UBUNTU-CVE-2026-31958","UBUNTU-CVE-2026-35536"],"upstream":["UBUNTU-CVE-2026-31958","UBUNTU-CVE-2026-35536"],"references":[{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8198-1"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-31958"},{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-35536"}],"affected":[{"package":{"name":"python-tornado","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.1-1ubuntu3.1+esm3"}]}],"versions":["4.2.1-1ubuntu2","4.2.1-1ubuntu3","4.2.1-1ubuntu3.1","4.2.1-1ubuntu3.1+esm1","4.2.1-1ubuntu3.1+esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"python-tornado","binary_version":"4.2.1-1ubuntu3.1+esm3"},{"binary_name":"python3-tornado","binary_version":"4.2.1-1ubuntu3.1+esm3"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:Pro:16.04:LTS","cves":[]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8198-1.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.3-1ubuntu0.2+esm3"}]}],"versions":["4.5.1-2.1~build2","4.5.2-1","4.5.3-1","4.5.3-1ubuntu0.1","4.5.3-1ubuntu0.2","4.5.3-1ubuntu0.2+esm1","4.5.3-1ubuntu0.2+esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"python-tornado","binary_version":"4.5.3-1ubuntu0.2+esm3"},{"binary_name":"python3-tornado","binary_version":"4.5.3-1ubuntu0.2+esm3"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:Pro:18.04:LTS","cves":[{"id":"CVE-2026-31958","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]},{"id":"CVE-2026-35536","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8198-1.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.3+really5.1.1-3ubuntu0.1~esm5"}]}],"versions":["5.1.1-4ubuntu1","5.1.1-4ubuntu5","6.0.3+really5.1.1-2","6.0.3+really5.1.1-2build1","6.0.3+really5.1.1-2build2","6.0.3+really5.1.1-3","6.0.3+really5.1.1-3ubuntu0.1~esm1","6.0.3+really5.1.1-3ubuntu0.1~esm3"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-tornado","binary_version":"6.0.3+really5.1.1-3ubuntu0.1~esm5"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:Pro:20.04:LTS","cves":[{"id":"CVE-2026-31958","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]},{"id":"CVE-2026-35536","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8198-1.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.0-3ubuntu0.1~esm5"}]}],"versions":["6.1.0-1build1","6.1.0-2","6.1.0-3","6.1.0-3build1","6.1.0-3ubuntu0.1~esm1","6.1.0-3ubuntu0.1~esm2","6.1.0-3ubuntu0.1~esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-tornado","binary_version":"6.1.0-3ubuntu0.1~esm5"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"cves_map":{"ecosystem":"Ubuntu:Pro:22.04:LTS","cves":[{"id":"CVE-2026-31958","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]},{"id":"CVE-2026-35536","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}]},"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8198-1.json"}},{"package":{"name":"python-tornado","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/python-tornado?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.4.0-1ubuntu0.5"}]}],"versions":["6.3.2-1","6.4.0-0ubuntu1","6.4.0-1","6.4.0-1build1","6.4.0-1ubuntu0.1","6.4.0-1ubuntu0.2","6.4.0-1ubuntu0.4"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-tornado","binary_version":"6.4.0-1ubuntu0.5"}],"availability":"No 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